US3498270A - All-welded furnace construction - Google Patents

All-welded furnace construction Download PDF

Info

Publication number
US3498270A
US3498270A US725764A US3498270DA US3498270A US 3498270 A US3498270 A US 3498270A US 725764 A US725764 A US 725764A US 3498270D A US3498270D A US 3498270DA US 3498270 A US3498270 A US 3498270A
Authority
US
United States
Prior art keywords
tubes
furnace
pass
walls
wall
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US725764A
Other languages
English (en)
Inventor
Walter P Gorzegno
Jacob Cooper
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Foster Wheeler Inc
Original Assignee
Foster Wheeler Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Foster Wheeler Inc filed Critical Foster Wheeler Inc
Application granted granted Critical
Publication of US3498270A publication Critical patent/US3498270A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
    • F22B37/10—Water tubes; Accessories therefor
    • F22B37/14—Supply mains, e.g. rising mains, down-comers, in connection with water tubes
    • F22B37/146—Tube arrangements for ash hoppers and grates and for combustion chambers of the cyclone or similar type out of the flues
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B29/00—Steam boilers of forced-flow type
    • F22B29/06—Steam boilers of forced-flow type of once-through type, i.e. built-up from tubes receiving water at one end and delivering superheated steam at the other end of the tubes
    • F22B29/061—Construction of tube walls
    • F22B29/062—Construction of tube walls involving vertically-disposed water tubes

Definitions

  • the corners of the furnace are comprised of tubes of the same pass to permit the lower or bottom corners to be welded together, and the layout of the passes is such that one pass will be adjacent in its longitudinal dimension to a pass which either immediately precedes or immediately follows it in the flow circuitry.
  • the invention is applicable to both a flat bottom type of furnace and a hopper bottom type of furnace.
  • the present invention relates to an all-welded furnace construction for vapor generators of the once-through type, and in particular to a novel all-welded construction for the furnace bottom.
  • the all-welded construction or design is that construction or design wherein the tubes or the fins of parallel finned tubes are welded together, for instance along their lengths, so that a surface comprised of the tubes is gas tight without the need for seal plates and/ or refractory.
  • a once-through vapor generator is defined as a generator wherein the flow is forced through the tubes of the generator without recirculation.
  • the flow was usually transmitted in a single tube pass defining the generator furnace walls, and then was transmitted through super-heating passes in a convection area of the furnace to a point of use.
  • present generators having a furnace section in the order of eighty by forty feet in width and depth, with large numbers of burners disposed on opposite front and rear walls of the furnace, it has become apparent that special precautions are necessary to assure an equal flow distribution in the tubes of the furnace walls. For instance, tubes in the center of a wall may have a greater heat absorption than tubes in a corner of the furnace, resulting in unequal or unbalanced fluid and metal temperatures, and flow upsets.
  • seal plates require considerable exact fitting and welding which is expensive in the field, and accompanied with the danger of accidental burning or cutting of tubular pressure parts.
  • the design and construction of the furnace bottom which has always been a complicated and expensive part of the construction of a vapor generator, is further complicated when the furnace is constructed of a plurality of passes in series by the differential thermal expansion stresses which result.
  • a further object of the invention is to minimize fit-up and field welding costs and to simply the furnace bottom construction.
  • the invention is applicable to two types of furnaces, a hopper bottom type furnace, or a flat bottom type of furnace which is coal, oil or gas fired.
  • a hopper bottom type furnace or a flat bottom type of furnace which is coal, oil or gas fired.
  • the furnace would be of the slag-tap type.
  • a rectangular upright furnace enclosure including first and second oppositely facing walls and side walls therebetween or intermediate the first and second walls.
  • a plurality of parallel upright finned tu-bes welded together define each of the walls and said furnace enclosure.
  • a plurality of headers are connected to predetermined groups of tubes to divide the furnace enclosure walls into a plurality of flow passes, there also being provided a plurality of downcomers connecting the passes so that the passes are in series.
  • the walls are divided preferably into at least three flow passes, with the oppositely facing first and second walls being predominantly comprised of tubes of the first and third passes, the intermediate side walls constituting tubes of the second pass.
  • the headers, and connections between the headers and tubes are arranged so that the intermediate second pass extends around the corners of the furnace enclosure to occupy portions of the ends of the first and second walls adjacent the intermediate walls, the upright corners thereby being comprised of tubes of the same pass.
  • the tubes of any one pass will always be adjacent to tubes of the same pass or of either a preceding or following pass, along the lengths thereof.
  • the sides of the floor adjacent the furnace side walls are comprised of tubes of the second pass, so as to avoid stress between the floor and side walls, and in the three dimensional corners consisting of the opposite first and second walls, the side Walls and the floor, the tubes defining each corner are all at the same temperature.
  • the remainder center portion of the floor is comprised of tubes of the first pass which then extend on upwardly in said first upright wall of the furnace enclosure.
  • the above arrangement permits welding the walls and floor together using the fin-tube all-welded construction in the lower portion or bottom of the furnace and eliminates or minimizes the use of seal plate and refractory and the accompanying disadvantages of both.
  • FIGURE 1 is a perspective partially broken-away view illustrating the invention in connection with a gas-fired flat bottom once through vapor generator or a slag-tap type of coal fired generator;
  • FIGURE 2 is a section view taken through line 22 of FIGURE 1;
  • FIGURE 3 is a perspective partially broken-away view of a dry ash hopper bottom type generator in accordance with the invention.
  • FIG- URES 1 and 2 there is illustrated a furnace enclosure 12 consisting of first and second (hereafter called front and rear walls) walls 14 and 16, and side walls 18 and '20 between or intermediate the front and rear walls.
  • first and second (hereafter called front and rear walls) walls 14 and 16 and side walls 18 and '20 between or intermediate the front and rear walls.
  • the generator can be fired by coal, gas, or oil by burner which are not shown and for coal firing the fiat bottom arrangement of FIGURE 1 would be provided with a suitable slag tap, also not shown.
  • the division wall is not required, but is utilized with the larger furnaces of today for the purpose of introducing further heat absorption surface into the furnace enclosure.
  • Each of the side and front and rear walls is made up of a plurality of upwardly extending parallel flow tubes while the floor is made up of a plurality of parallel horizontally extending tubes, which extend parallel to the side walls between the front and rear walls, and the division wall is made up of a plurality of tubes which enter the furnace enclosure in a horizontal direction and are disposed in a vertical plane and which are then bent to extend upwardly in the middle of the furnace enclosure in a vertical plane parallel to the sidewalls 18 and 20.
  • the division wall makes up a first pass A, receiving a fluid flow from the economizer (not shown) of the generator, and from the division wall the fiow is transmitted to a first furnace enclosure pass 1 made up of tubes of the bottom wall 22 of the furnace and also tubes of the front wall 14. From the outlet header of the front wall, the flow is transmitted to a second pass 2 consisting primarily of tubes of the sidewalls 18 and 20 of the furnace enclosure. Finally, the flow is transmitted through a third pass 3 of the furnace enclosure defining primarily the rear wall 16 of the enclosure.
  • the arrangement can be easily visualized by referring specifically to the inlet headers for the various passes.
  • a first pair of headers comprising opposite vertically extending headers 26 and 26 outside of the upright rear and front walls 16 and 14.
  • the flow from he e onomizer ection of the generator is distributed equally to these two headers by conduits 27 and 27 for uniform distribution of flow in the division wall.
  • the flow is through a suitable downcomer 29 to a single header 28 for the first enclosure pass 1.
  • the header 28 is parallel to and outside of the rear Wall 16 in a horizontal plane approximately coplanar with the floor or bottom wall 22 and is connected to a center section 22a of tubes of the flat bottom wall 22, making up most of the bottom wall or floor.
  • FIGURE 2 illustrates the construction of the furnace where the pass 1" floor tubes intersect the pass 3 wall tubes.
  • the tubes of pass 3 are all fin-weldcd together, and the pass 1 tubes which intersect the pass 3 wall are seal welded to the latter.
  • the pass 3 tubes are all aligned in a vertical plane, and the pass 1 tubes are for the most part in a horizontal plane within the furnace enclosure, except in the area adjacent to the pass 3 wall.
  • the tubes are grouped into groups of four and the a, b and d tubes are bent downwardly and towards the c tube to pass through the pass 3 wall in the same vertical plane as the pass 0 tube, aligned vertically with the latter.
  • the tubes are connected to header 28 in groups of two, as shown.
  • the pass 2 tubes occupy sufficient areas of these walls, perhaps a dozen tubes or a foot or more in from either side wall, so that the differences in expansion experienced between passes 2 and 3 and passes 2 and 1 are distributed over a number of tubes before the corners are reached.
  • the tubes are at the same temperature.
  • the tubes of the bottom wall or floor are grouped together in groups of four to pass in a vertical plane through the vertical wall and a fairly long plate member 50 sealing the bottom and rear wall corner takes up the stresses caused by any temperature differences between the tubes of these walls. In the very critical three dimensional corners the tubes are all at the same temperature.
  • the invention minimizes stresses at t e bottom of the furnace enclosure, permits welding most of the furnace enclosure walls including the floor together to produce a tighter enclosure and reduces the use of seal plates and fit-up and welding which accompanies such use.
  • a further advantage of the invention should also be evident, namely that the passes are arranged so that for the most part the end-most tubes of any one pass will be adjacent to tubes of either a succeeding pass or a following pass.
  • the pass 1 tubes will not be adjacent to the pass 3 tubes along a longitudinal seam.
  • the side walls there is obviously no problem.
  • the end-most tubes of pass 1 are adjacent to pass 2 tubes.
  • the end-most tubes of pass 3 are adjacent to pass 2 tubes.
  • FIGURE 3 illustrates the invention with a hopper bottom type furnace.
  • coal is usually burned, although the furnace may also be oil fired.
  • the hopper is usually provided with a water seal, and the dry ash discharges through the hopper into a suitable container at the bottom of the hopper.
  • Pass 1 is connected in series with pass 2 the tubes of which make up the side walls 64 and 66 of the furnace and narrow end portions 60b and c and 62b and c of the front and rear walls 60 and 62.
  • pass 2 has enough tubes or occupies a sufficient part of the front and rear walls so that the stresses existing in these walls will be distributed over a fairly long distance before reaching the corners.
  • a division wall 70 can be utilized in this type of furnace to make up a pass A passing upwardly in the middle of the furnace. These tubes of the division wall pass through the sloping hopper portions of the front and rear walls and then are bent to extend upwardly in a plane parallel to and intermediate the two side walls.
  • Pass A is furnished water from the economizer by downcomers 72 and headers 74. Only one downcomer 72 and one header 74 are shown but it will be understood that another of each of these elements is provided on the obscured side of the furnace.
  • fluid is carried by downcomer 75 to the header 76 which feeds the pass 1 tubes.
  • the fluid is carried down downcomers 78 and 80 to headers at the bottoms of the pass 2 tubes, that is the tubes which make up the side wall 64 and 66, the end portions 60b and 600 of the front wall 60 and the end portions 62b and 620 of the rear wall 62.
  • the fluid is fed down downcomer 82 to header 84 which distributes fluid to the pass 3 tubes in the rear wall 62.
  • An all-welded furnace construction comprising a rectangular furnace enclosure including first and second oppositely facing walls and side walls therebetween;
  • each header being connected to preselected groups of tubes so that said enclosure is divided into a plurality of flow passes;
  • headers and tube connections being arranged so that the tubes adjacent to and on opposite sides of the enclosure corners defining each corner will be of the same flow pass.
  • furnace enclosure comprises at least three flow passes in series, the first wall comprising predominantly tubes of the first pass and the second wall comprising predominantly tubes of the third pass, said side walls and areas of said first and second walls adjacent the side walls comprising tubes of the second pass.
  • furnace enclosure further includes a floor, the floor comprising predominantly tubes of the first flow pass which are bent to extend upwardly in said first wall, the areas of said floor adjacent the side walls comprising tubes of the second pass which are also bent upwardly in the first wall coplanar with the first pass tubes to define said areas of the first wall adjacent the side walls.
  • An all-welded furnace construction comprising a rectangular furnace enclosure including first and second oppositely facing walls and third and fourth walls therebetween;
  • header means connected to the furnace enclosure tubes including the floor tubes so that the enclosure including the floor is divided into a plurality of flow passes;
  • the header means for the third and fourth walls also supplying a cooling fluid to a limited number of the floor tubes and a limited number of first and second wall tubes adjacent the third and fourth walls whereby the three-dimensional corners defined by the floor and four Walls are comprised of tubes at the same 7 temperature.
  • An all-welded furnace construction comprising a rectangular furnace enclosure including first and second oppositely facing walls and third and fourth walls therebetween;
  • said first and second walls being sloped to converge inwardly near the bottom of the furnace enclosure to define a furnace hopper bottom;
  • a plurality of header means connected to the furnace enclosure tubes so that the enclosure is divided into a plurality of flow passes;
  • the header means for the third and fourth walls also UNITED STATES PATENTS supplying a cooling fluid to a limited number of 3,237,612 3/ 1966 Koch et 122406 tubes of the sloping hopper bottom of the first and 3,324,837 6/1967 GOTZegnO et 4 second Walls adjacent the third and fourth Walls 5 3,344,777 10/ 1967 Gorzegno 122406 whereby the corners of the hopper are comprised of tubes at the Same temperature.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Automatic Cycles, And Cycles In General (AREA)
  • Fluidized-Bed Combustion And Resonant Combustion (AREA)
US725764A 1968-05-01 1968-05-01 All-welded furnace construction Expired - Lifetime US3498270A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US72576468A 1968-05-01 1968-05-01

Publications (1)

Publication Number Publication Date
US3498270A true US3498270A (en) 1970-03-03

Family

ID=24915868

Family Applications (1)

Application Number Title Priority Date Filing Date
US725764A Expired - Lifetime US3498270A (en) 1968-05-01 1968-05-01 All-welded furnace construction

Country Status (5)

Country Link
US (1) US3498270A (enrdf_load_stackoverflow)
ES (1) ES366653A1 (enrdf_load_stackoverflow)
FR (1) FR2007599A1 (enrdf_load_stackoverflow)
GB (1) GB1265741A (enrdf_load_stackoverflow)
NL (1) NL159178B (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0128020A1 (en) * 1983-06-03 1984-12-12 Fluidised Combustion Contractors Limited Fluidised bed combustion apparatus
EP0352488A1 (de) * 1988-07-26 1990-01-31 Siemens Aktiengesellschaft Durchlaufdampferzeuger
WO1996012140A1 (de) * 1994-10-17 1996-04-25 Austrian Energy & Environment Sgp/Waagner Biro Gmbh Kühlflächenauskleidung
US20090209973A1 (en) * 2005-06-10 2009-08-20 East Michael C Surgical apparatus and the use thereof
JP2010540246A (ja) * 2007-10-08 2010-12-24 フォスター ホイーラー エナージア オサケ ユキチュア 遠心分離機アセンブリ
CN105333414A (zh) * 2015-11-30 2016-02-17 北京热华能源科技有限公司 一种可插拔快装自密封式省煤器

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2170588T3 (es) * 1998-06-10 2002-08-01 Siemens Ag Generador de vapor calentado con combustible fosil.
DE19858780C2 (de) * 1998-12-18 2001-07-05 Siemens Ag Fossilbeheizter Durchlaufdampferzeuger
DE19914760C1 (de) * 1999-03-31 2000-04-13 Siemens Ag Fossilbeheizter Durchlaufdampferzeuger

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3237612A (en) * 1963-10-01 1966-03-01 Babcock & Wilcox Co Forced flow vapor generating unit
US3324837A (en) * 1964-05-27 1967-06-13 Foster Wheeler Corp Multiple pass design for once-through steam generators
US3344777A (en) * 1965-10-22 1967-10-03 Foster Wheeler Corp Once-through vapor generator furnace buffer circuit

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3237612A (en) * 1963-10-01 1966-03-01 Babcock & Wilcox Co Forced flow vapor generating unit
US3324837A (en) * 1964-05-27 1967-06-13 Foster Wheeler Corp Multiple pass design for once-through steam generators
US3344777A (en) * 1965-10-22 1967-10-03 Foster Wheeler Corp Once-through vapor generator furnace buffer circuit

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0128020A1 (en) * 1983-06-03 1984-12-12 Fluidised Combustion Contractors Limited Fluidised bed combustion apparatus
WO1984004954A1 (en) * 1983-06-03 1984-12-20 Fluidised Combustion Contract Fluidised bed combustion apparatus
EP0352488A1 (de) * 1988-07-26 1990-01-31 Siemens Aktiengesellschaft Durchlaufdampferzeuger
US4926799A (en) * 1988-07-26 1990-05-22 Siemens Aktiengesellschaft Continuous flow steam generator
WO1996012140A1 (de) * 1994-10-17 1996-04-25 Austrian Energy & Environment Sgp/Waagner Biro Gmbh Kühlflächenauskleidung
US5775265A (en) * 1994-10-17 1998-07-07 Austrian Energy & Environment Sgp/Waagner-Biro Gmbh Cooling surface cladding
US20090209973A1 (en) * 2005-06-10 2009-08-20 East Michael C Surgical apparatus and the use thereof
JP2010540246A (ja) * 2007-10-08 2010-12-24 フォスター ホイーラー エナージア オサケ ユキチュア 遠心分離機アセンブリ
CN105333414A (zh) * 2015-11-30 2016-02-17 北京热华能源科技有限公司 一种可插拔快装自密封式省煤器
CN105333414B (zh) * 2015-11-30 2017-07-21 北京热华能源科技有限公司 一种可插拔快装自密封式省煤器

Also Published As

Publication number Publication date
NL159178B (nl) 1979-01-15
NL6906673A (enrdf_load_stackoverflow) 1969-11-04
GB1265741A (enrdf_load_stackoverflow) 1972-03-08
ES366653A1 (es) 1971-07-16
FR2007599A1 (enrdf_load_stackoverflow) 1970-01-09

Similar Documents

Publication Publication Date Title
US3498270A (en) All-welded furnace construction
US3368534A (en) Multiple pass design for once-through steam generators
US4245588A (en) Vapor generating system having a division wall penetrating a furnace boundary wall formed in part by angularly extending fluid flow tubes
US2987052A (en) Wall construction for pressurized furnace
US3556059A (en) Two-pass furnace circuit arrangement for once-through vapor generator
US5273002A (en) Water tube boiler
US3665893A (en) Vapor generator tube arrangement
US3872836A (en) Coal-fired generator of medium to large capacity
US3105466A (en) Vapor generator
US3545409A (en) Offset mix tubes
US2948267A (en) Steam generating unit having a superheater and reheater each including a radiant section and a convection section
US2999483A (en) Furnace wall and support construction
US3343523A (en) Vapor generator
US3247830A (en) Forced flow steam generator having plural tube systems
US2797667A (en) Controlled circulation boiler with novel dual furnace
GB1022838A (en) Supercritical forced through-flow vapor generator with improved wall arrangement
US3007459A (en) Forced flow vapor generating unit
US3457903A (en) Furnace floor arrangement
US3196842A (en) Furnace
US3358650A (en) Water cooled furnace joint for mixing header arrangement
US3612003A (en) Forced through flow steam generator
US2979041A (en) Vapor generator
US3117558A (en) Integral tube and wall panels
US3685496A (en) Steam boiler having a water space traversed by a flue gas duct
US3612006A (en) Expansion seal